"But it's not about seeing McLaren with problems but because they are going faster with a very similar engine. So the power unit is good and its reliable, which is why they're happy," he said.

"Honda did not like breaking with McLaren, who have continued to criticise them, but it is how it is. Now they are more calm and satisfied that their engine is good and it will improve more," Kawai added.

Another Japanese journalist, Tsuyoshi Fukue, continued: "They (Honda) say it's easier to work with Toro Rosso."

That may be due in part to team boss Franz Tost, who knows Honda well after working closely with Ralf Schumacher during his Japanese racing career in the 90s.

Tost is quoted by AS newspaper: "We are very happy with Honda.

"I am sure they will offer us a very competitive package, that during the season we will advance a lot and for the final part we will have a very competitive car.

"Our goal is to be at the front of the middle zone. I don't care about McLaren, but I am sure that, in the end, we will have a more competitive package than theirs," Tost added.